Portable mixing plant



July 9, 1940. w. E. PROUT Er A1.

PORTABLE MIXING PLANT 17, 1938 4 shets-sheet 1 Filed Dec.

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WILLIAM E- PROUT JOHN YouNT July 9, 1940- w. E. PROUT er Ax. 2,207,303

PORTABLE MIXING PLANT Fild Dec. 1'7, 1938 4 Sheets-Sheet 2 @3M 3 Jol-1N YoUNT fwwm July 9, 1940- w. lE. PROUT ET Al. 2,207,303

PORTABLE MIXING PLANT Filed Deo. 17, 1938 4 Sheets-Sheet 5 Qrwwvbo WILLIAM E- PROUT JOHN You NT July 9, 1940. w. E. PROUT ET AL.

PORTABLE MIXING PLANT Filed Dec. 17, 1938 4 Sheets-Sheet 4 Qrwvwkw WILUAM E- PROUT JOHN YouNT fm fw@ Patented July 9, 1940 APri'rlzrrr ol-FICE 2201303 .PORTABLE MIXING PLANT William E. Prout, Youngstown, Ohio, and John Yount, Pittsburgh, Pa.

Application December 17, 193s, serial No. 246,344

6 Claims.

This invention relates to a mixing plant .for mixing proportioned quantities of aggregate and bituminous materials to pro-vide a mixture suitable for road paving operations and the invention has as its primaryobject the provision of a plant for the purpose stated which is efficient in use, economical to construct, and which may readily be trans-portedirom place to place with a minimum of labor, equipment and time.

Although heretofore various arrangements and expedients have been adopted to render plants of the above type portable,a consideration of the prior structures will render apparent their limitations and disadvantages and it is, accordingly, a more specific object of the invention to provide a portable road metal mixing assembly in-Which the shortcomings of the prior arrangements are obviated. The utility involved in the portability of the plant is predicated, primarily,in the ability to maintain the source of mixed paving materials close to the road building or maintenance operations in which the material is used, thus reducing the length of vehicular haul required. For maximum efficiency it is necessary that the plant be capable of being converted from its operating condition to its transporting condition and-vice versa in a short period of time and without the use of any special equipment. Likewise, the plant, when in compacted condition for transporting, should be capable of being transported by a readily available traction device. When assembled for operation, the plant must deliver the mixed material at a height convenient for loading onto trucks and as it is impractical to employ elevating means to lift the material, the common practice is to elevatethe hoppers, batchers and mixing mill assembly so that the component materials flow into the mill and the mixed material flows into the truck -by gravity. Such a unit, however, is too unstable for transporting and too high for allowable road clearances and therefore some means must be provided to readily raise and lower the assembly mentioned and it is therefore another object of the invention to provide an arrangement whereby the number of elements and total weight required to be raised and lowered is reduced to a minimum.

A further object of the invention is the provision of improved means for raising and lowering the material mixing mill and essential ancillary equipment.

Still another object of the invention is the provision of an improved frame structure for supporting the mill, hoppers, motor and other elements constituting the mixing plant.

Yet another object of the invention ,is the provision of improved supporting and tractive means for the plant for both xed and mobile positions.

These and'other objects and advantages of the invention will become apparent from a consideration of the following detailed specification and the accompanying drawings wherein there is specifically disclosed a preferred embodiment of the invention.

In the drawings:

Figure 1 is a side view of a portable mixing plant constructed according to the teachings of Amy invention and shows the plant assembledin operative position; v

Figure 2 is a sideview of the plant of Figure 1 in transportable collapsed condition and illustrates the manner in which the plant is moved;

Figure 3 is a cross-sectional view taken along theline 3-3 of Figure 1 looking in the direction of the arrows; Y

Figure 4 is a rfragmentary View showing the `means employed to raise and lower the frame section which carries the mixing mill;

Figure 5 is a top view of hoisting mechanism of Figure 4; and n Figures 6 and '7 vare structural details of the plant .supporting frame.v Y

A plant for preparing road paving materials,

as concerns the present invention, consists essentially of a hopper for storing gravel or other i aggregate, .a batcher for weighing out the aggregate, a batcher for the component bituminous material and a mixing mill, commonly termed a pug mill for thoroughly intermixing the aggregate and bituminous binder. Referring to Figurev l, which illustrates such a plant set up for operation, these elements are schematically shown at andv designated as Ill, II, I2 and I3, respectively. In operation, slag, gravel, or other aggregate material is conveyed to the hopper IIJ by any suitable means, as the chain bucket hoist rIll which extends down into or below any suitable source of supply and which is preferably driven by a motor I5. supported on a structural member It interconnecting the frame of the hoist and the frame of the plant proper. in accordance usual practice, the hopper Ill may be provided with two compartments Ia and Inh to store different 'kinds or grades of material and in actual practice the Ahoist I4 extends considerably above the top of hopper Ill to a point more centrally located, thereby enabling delivered material tov be selectively diverted into one or the other of the compartments by means of a baille is-Well understood in thev art.

In carrying out our invention, the frame supporting the various parts of the mixing plant is constructed of three separable sections, designated generally on the drawings as A, B and C. The outer or end sections A and C each comprise a pair of spaced parallel upwardly extending members I8, H-shaped in cross section and so oriented that channels of the members of one frame section face channels of the members of the other frame section to provide, in effect, guideways for the slidable support of corner post members of the center frame section B. Rigidly to indicate the weight of material therein but as secured to the members I8 of the frame section A and extending horizontally therefrom adjacent the lower ends thereof is the base i9 which is held in position by the diagonal braces 28 secured at their lower outer ends to the outer end of the base I9 and at their-upper inner ends to the upper portionsI of the adjacent members I8. Base I9 may conveniently support the pug mill driving motor 2I although it should be understood lthat this motor may be mounted on the center frame section C along with the mill or at other locations on the assembly. A housing 22 may be built over the base I9 to house and protect the motor 2|, or other electrical or mechanical equipmentof the plant assembly. Supporting the base i9 is the pair o-f road engaging wheels 23 which are preferably doubly pneumatic tired and spring mounted in a manner common to vehicular construction.

Rigidly secured to the members I8 of the frame section C and extending horizontally therefrom adjacent the lower ends thereof is the structural platform 25 which is rigidly held in proper position by the braces 26 which are connected at their Outer ends to the outer end of the platform 25 and at their inner ends to the upper portions of the adjacent members I 8. Platform 25 is provided, primarily, to provide means whereby the plant, when in collapsed transportable condition (see Figure 2), may be coupled with a motor tractor of conventional design and to this end a beveled disk ,33 having a centrally disposed downwardly extending pin 34 is secured to the underside of the platform 25. As shown in Figure 2, the disk 33 and pin 34 are adapted to cooperate with a coupling 35, commonly termed a fth wheel, of a conventional tractor 36. Platform 25 may also be utilized to support a tank 21 for the storage of asphatic oil or other bituminous material used in the preparation of the road metal material and, in accordance with usual practice, a heating means, schematically shown at 28, may be built into the tank 21. A motor driven pump 30 having an inlet pipe 3l connected with the tank and an outlet pipe 32 extending to the bituminous material batcher I2 is operative to pump the material from the tank and may also be conveniently supported on the platform 25.

The intermediate frame section B consists of a box-like assembly of structural members including four spaced corner posts 40 which posts are H-shaped in cross-section and have outer dimensions suiciently small to nest within the channels of the frame members I 8. Note Figures 5 and 6. A platform 4`I rigidly connects the lower ends of the columns 40 and horizontally extending frame elements 4Iu ties together the upper ends of the members 40 and provides an immediate support for the aggregate hopper IU. The latter is provided with a readily removable top portion Ic which is removed when the plant is collapsed for transportation and two outlet valves 5Ia and 5IbA for controlling the flow of materials from the compartments lUa and Ib respectively. 'Ihe valves 5Ia and 5Ib are controlled by any suitable hand operating means 52a and 52h respectively. Aggregate batcher II is supported beneath the hopper I0 on a scale beam shown schematically at 54 and an indicator 55 may be employed to show the amount of material in the batcher. A valve 58 is provided to control the flow of material from the batcher II into the pug mill I3. The bituminous materia] batcher I 2 is likewise provided with means the aggregate and bituminous material weighing means form no part of the invention they have been omitted in part for sake of brevity. A manually controlled valve 51 controls the iiow of the bituminous binder from the batcher I2 into the pug mill. A pair of side members 42 intermediate the upper and lower ends of the frame section B may be provided to lend rigidity to the structure.

Pug mill I3, being of conventional design, is provided with a pair of parallel shafts 43 each having a plurality of mixing blades 44 extending radially outward therefrom. See Figures 1, 2 and 3. Shafts 43 are rotated in opposite dlrections by the gear trains 41 which is connected with the jack shaft 49 mounted on frame section A. A link chain 48 connects the jack shaft with the gear train and a belt or chain 50 connects the motor 2l with the jack shaft. When the frame is to be collapsed for the transporting of the plant, the chain 48 is rst remo-ved. With the center frame section B in elevated position as shown in Figure l of the drawings, the platform 4I is elevated sufficiently to allow a motor truck of conventional design to pass underneath thereof. Asthe mixing of a batch of the road making material is completed, a gate 45 in the lower wall of the pug mill I3 is opened by any suitable means, as the steam cylinder 46, and the mixed material falls into the body of a truck positioned below.

Referring now to Figures l, 4 and 5, the means employed to raise and lower the center frame section B consists of a pair of conventional chain blocks 18 coupled with a pair of parallel shafts 14 about which are wound the lifting cables 88. Chain blocks 10 are conveniently sup-ported on the frame sections A and C, respectively, either by means of a bracket 1I or by other suitable means and are each provided with a manually engageable endless chain 12 and a slow speed driving shaft 13. the shafts 14 by the chains 15 trained over sprockets keyed to the shafts involved. As shown in Figure 5, the shafts 14 are journaled on the vertical columns I8 of the frame sections A and CV and are positioned so as not to interfere with vertical movement of the section B. Each shaft 14 is provided with one or more drums 16 on which is wound the cables 80, the cables being looped under pulleys 19 carried by parallel shafts 11 secured to the lower end of the frame section B. 'I'he iixed ends of the cables 80 are anchored to the fixed frame sections A and C at 8l. It should be obvious that, with the parts assembled, as shown, manipulation of the chains 12 will result in the center frame section B being raised or lowered relative to the end sections A and C.

To provide additional support for the hopper, batchers, and mill when the plant is in operation, foot members 6I (see Figure 1) having bottom load bearing webs 6Ia are attached vto the lower The latter are coupled with ends of the H-columns I8 by means of the splice plates 62 and bolts 63. Note Figure 7. When the plant is prepared for transportation, the foot members 6I are removed.

To lend` rigidity to the structure when assembled for operation, an X brace 60' is secured to each side of the assembly which braces yare bolted at their lower ends to the H-columns I8 and at their upper ends to the corner posts 40 of the center frame section B. In addition to this tie, the sections are further secured together by a plurality of bolts 64 which pass through portions of the nesting members I8 and 40. Note Figure 6. When it is desired to lower frame section B, the X braces are det-ached from their upper shown position and lowered to a position where both upper and lower ends are bolted to the H columns I8. Bolts 64 are then Vremoved and the section B including the members 40 is then free to be lowered by action of the chain blocks in the manner described above. Upon completion of the lowering operation, bolts 64 are reinserted in appropriately provided yaligned holes to again securelybolt the frame sections together after which the X braces may beremoved, if desired.` To prevent binding between the H Vmembers I8 and 40 during relative Vertical movement of the section B, a metallic bar 65 is welded or otherwise suitably secured in each of the channels of members I8 into which members 48 will extend. The channels provided by the iianges of members I8 and the bars 65 provide satisfactory guides for the slidable movement of the center section when the latter is being raised or lowered. The guides thus provided are maintained in their proper spaced parallel relation by the X braces. 60. The steps 68, providing ready access to the mill and various controlling devices of the plant when the plant is in operation, are detachably secured to the frame and are removed when the plant is prepared for transportation.

It should now be apparent that we have provided an apparatus which accomplishes the objects initially set out. With a minimum amount of labor and without the use of any separate equipment, the plant may readily be collapsed and prepared for movement to a new location of use. Such preparation is accomplished simply by lowering a portion of the frame and backing the fth wheel of a conventional motor tractor under a portion of the same whereby tractive force may be applied. When collapsed, the plant, including the wheels 23, is similar in general organization, weight distribution and size to .a conventional large semi-trailer used for hauling freight and as such can be rapidly moved from place to place over all highways suitable for truck traic without the necessity of any special preparation or precaution. The above specifically disclosed embodiment of our invention should be considered as illustrative only as obviously innumerable changes may be made therein without departing from the spirit or scope of our invention.

What we claim is:

l. In a portable mixing plant the combination of an intermediate box-like frame for the support of a material mixing device, a material mixing device carried in the lower portion of said frame, end frames extending horizontally outward from either end of said intermediate frame, road engaging wheels attached to and supporting one of said end frames, means. carried with the other of said end frames to engage and be supported by a. motor tractor whereby said plant when in 'transportable condition assumes gen-l erally asemi-trailer form, and means toelevate said intermediate frame relative to said end frames to assemble said plant for operation lwhereby* sufcientv vertical interval may be attained between the normal supporting surface ofthe plant and the bottom of the intermediate frame to permit conventional material transporting trucks to pass underneath the intermediate frame.

2. In a portable mixing plant the combination of an intermediate box-like frame for the support of a material mixing device, a material mixing device carried in the lower portion of said frame, said frame being provided with vertically extending end members on either end thereof, end frames extending horizontally outward from either end of said intermediate frame, said end framesV having vertically extending members normally abutting said vertically extending members of said intermediate frame, road engaging wheels attached vto and supporting one of said end frames, means carried with the other of said end frames to engage and be supported by aof an intermediate box-like frame for the support of a material mixing device, a material mixing device carried in the lower portion of said frame, end frames extending horizontally outward from either end of said intermediate frame, road engaging wheels attached to and supporting one of said end frames, means carri-ed with the other of said end frames to engage and be supported by a motor tractor whereby said plant when in transportable condition assumes generally a semi-trailer form, and means lto elevaate said intermediate frame relative to said end frames to assemble said plant for operation whereby suiiicient vertical interval may be attained between the normal supporting surface of the plant and the bottom of the intermediate frame to permit conventional material transporting trucks to pass underneath the intermediate frame, said elevating means comprising a chain block secured to one ofsaid end frames, a shaft journalled in one of said end frames, means connecting the output shaft to said block with said rst mentioned shaft, and a cable wound around said firstmentioned shaft and having one end secured thereto, the other end of said cable being connected with the lower portion of said intermediate frame.

4. In a portable mixing plant the combination of an intermediate box-like frame for the support of a material mixing device, a material mixing device carried by said frame, said frame being provided with vertically extending end members on either end thereof, end frames extending horizontally outward from either end of said intermediate frame and being provided with channeled vertical members adapted to receive the outerv portable condition assumes generally a semitrailer form, and means to move said intermediate frame vertically along said channeled mem- .bers to assemble said plant for operation whereby suiicient vertical interval may be attained between the normal supporting surface of the plant and the bottom of the intermediate frame to permit conventional material transporting trucks to pass underneath the intermediate frame.

5. In a portable mixing plant the combination of an intermediate box-like frame for the support of a material mixing device, a material mixing device carried by said frame, said frame being provided with vertically disposed members on either end thereof, end frames extending horizontally outward from either end of said interlmediate frame and being provided withy vertically disposed members overlying said vertically disposed members of said intermediate frame when the plant is in collapsed condition for transportation, a power device for driving said material mixing device supported by certain of said end frames, road engaging wheels attached to and supporting one of said end frames, means carried with the other of said end frames to engage and be supported by a motor tractor whereby said plant when in transportable condition assumes generally a semi-trailer form, and means to elevate said intermediate frame relative to said end frames to assemble said plant for operation whereby sufficient vertical interval may be 'attained'between the normal supporting surface of the plant and the bottom of the intermediate frame to permit conventional material transporting trucks to pass underneath the intermediate frame.

6. In a portable mixing plant the combination of an intermediate box-like frame for the support of a material mixing device, a material mixing device carried by said frame, said frame being provided with vertically disposed members on either end thereof, end frames extending horizontally outward from either end of said intermediate frame and being provided with Vertically disposed members overlying said vertically disposed members of said intermediate frame:

tained between the normal supporting surface of the plant and the bottom of the intermediate frame to permit conventional material transporting trucks to pass underneath the intermediate frame and between said end frames.

WILLIAM E. PROUT. JOHN YoUNT. 

